This invention pertains to a releasable locking device, which has an intended use at a beam-to-column connection in a storage rack, such as a pallet rack. This invention also pertains to a storage rack, such as a pallet rack, which comprises the releasable locking device.
In a storage rack, it is common to connect a beam to a column via a flanged member having a side flange welded to one end of the beam and a front flange, from which fasteners having inner heads project into similarly shaped apertures in a front wall of the column. Commonly, the apertures are shaped so that the inner heads of the fasteners can pass through upper regions of the apertures but not through lower regions of the apertures. Thus, the flanged member must be lifted to permit the inner heads of the fasteners to pass through upper regions of the apertures.
At an early date, it was realized that if the beam or the flanged member were struck by an object, such as a pallet, as the object was being lifted, the object could dislodge the flanged member from the column unless a latching or locking device was provided. Various latching or locking devices have been disclosed for latching or locking beams to columns.
Many prior patents disclose such latching or locking devices at beam-to-column connections in storage racks. One example is disclosed in U.S. Pat. No. 5,624,045 and U.S. Pat. No. 5,713,367, in which the fasteners are described as connecting pins and the disclosures of which are incorporated herein by reference. Other examples, which employ spring-biased pins, are disclosed in U.S. Pat. No. 3,330,583, in U.S. Pat. No. 4,074,814, the disclosure of which is incorporated herein by reference, and in U.S. Pat. Nos. 5,938,367 and 6,203,234, U.S. Pat. No. 6,155,441, U.S. Pat. No. 6,230,910, and U.S. Pat. No. 6,352,164. A latching or locking device of related interest is disclosed in U.S. Pat. No. 2,442,693.
This invention provides a releasable locking device comprising a housing, a locking pin, and an outer sleeve, which a user can pull to release the releasable locking device. The housing has a lateral wall, which has an elongate slot, an outer end, and an inner end. The housing has an end wall closing the outer end and is open at the inner end. The locking pin, which has a internal portion movable inside and along the lateral wall of the housing and which has a locking portion, is movable between a retracted position wherein the internal portion of the locking pin is spaced from the end wall of the housing by a comparatively lesser distance and an extended position wherein the locking portion of the locking pin extends from the inner end of the housing and wherein the internal portion of the locking pin is spaced from the end wall of the housing by a comparatively greater distance.
The locking pin is biased, as by a coiled spring acting between the end wall of the housing and the internal portion of the locking pin or by an elastomeric member acting therebetween, toward the extended position. The outer sleeve, which is movable outside and along the lateral wall of the housing, is connected to the locking pin via a connecting pin extending from the locking pin, through the elongate slot. The outer sleeve is connected to an end of the connecting pin.
Preferably, the elongate slot has two closed ends, which limit movement of the locking pin between the retracted and extended positions. Preferably, the elongate slot is one of two parallel slots, each slot being located on an opposite side of the lateral wall of the housing, the connecting pin extending through the locking pin, through each slot, and being connected to the outer sleeve at each end of the connecting pin. Preferably, the outer sleeve has a flange to facilitate pulling of the outer sleeve to move the locking pin toward the retracted position.
This invention also provides a storage rack comprising a column, a beam, and a releasable locking device, as described above. The column has a vertical array of fastener-receiving apertures, each having an upper region and a lower region and each having a margin, and a beam having an end flange, to which plural fasteners are mounted. Each fastener has a distal portion adapted to be inserted into the upper region of an associated one of the fastener-receiving apertures and to engage an inner margin of the same one of the fastener-receiving apertures, at the lower region of the associated one of said apertures, so as to prevent the distal end from being withdrawn unless and until the distal portion is elevated.
Many prior patents disclose such latching or locking devices at beam-to-column connections in storage racks. One example is disclosed in U.S. Pat. No. 5,624,045, in which the fasteners are described as connecting pins and the disclosure of which is incorporated herein by reference. Other examples, which employ spring-biased pins, are disclosed in U.S. Pat. No. 3,330,583, U.S. Pat. Nos. 5,938,367and 6,203,234, U.S. Pat. No. 6,155,441, U.S. Pat. No. 6,230,910, and U.S. Pat. No. 6,352,164.
In the storage rack provided by this invention, the housing of the releasable storage device is mounted to the end flange and opens at the inner end of the housing to a hole in the end flange. The hole is aligned with the upper region of a selected one of the fastener-receiving apertures, whereby, in the extended position, the locking pin extends through the hole in the end flange, into the upper region aligned with the hole.